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What is the use of the Map.prototype.keys method in JavaScript Maps ?

In JavaScript, the Map.prototype.keys method is used to get an iterator object that contains the keys of a Map. The iterator object follows the iterable protocol, allowing you to loop through the keys using methods like next() or using a for...of loop.

Syntax:

myMaps.key();

Example: Below is an example of a key method in a map.




let myMap = new Map();
 
myMap.set('key1', 'value1');
myMap.set('key2', 'value2');
myMap.set('key3', 'value3');
 
// Get an iterator for the keys of the Map
let keysIterator = myMap.keys();
 
// Use the iterator to loop through the keys
let nextKey = keysIterator.next();
while (!nextKey.done) {
  console.log(nextKey.value);
  nextKey = keysIterator.next();
}

Output
key1
key2
key3

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